It 


U.  S.  DEPARTMENT  OF  AGRICUL  ttJRE, 

BUR]   vr  OF  PLANT  INDUSTRY     Cireulai   No 
u    i    OALLOWAY,  i      •  Bui 


SOME  CONDITIONS  [NFLUENCING 
THE  YIELD  OF  HOPS. 


II  Y 


W.  W.  STOCKBERGER,  Pharmacognosist, 
JAMES  THOMPSON,  Expert, 

DrI  O-Pl  INT    I  w  !  STIG  \  I  i'  '\-. 


I-.  .m;     in 


»M-.«iic«  :  OC 





■EPOSITORY 


1  fir.  56] 
2 


Bl  REAL    OF  PLANT   INOISTRY. 


Chiif  of  Bureau,  Beverlx  T.  Galloway. 
Assistant  Chief  of  Bureau,  G.  Harold  Powell. 

EditO)  .    .1-     E.    K'  ICK  WELL. 

Chief  Clerk,  James  E.  .Junes. 


I:     r     . 


SOME  CONDITIONS  INFLUENCING  Till; 
YIELD  OF  HOPS. 


INTRODUCTION. 

In  certain  of  the  hop-growing  sections  <>t'  the  United  States  the 
opinion  i-  frequently  expressed  thai  there  has  been  a  progressive  de- 
cline in  tin'  :i 1 1 n 1 1 ;il  average  yield  per  acre  extending  over  ;i  term  of 
years.  In  other  sections  growers  believe  thai  the  yields  are  ;it  least 
as  great  now  as  the}  have  ever  been.  Some  supporl  for  each  view  i- 
found  in  Table  I.  adapted  from  Bulletin  N<>.  -"'<i  of  the  Bureau  of 
Statistics,  I  .  S.  Department  of  Agriculture. 

Tabu    I       i    cragi    yield  of  /c;/>n.   by  States,   foi    /'"    <■  cam    /^s".   1890, 

and   /.'"■". 


■ 


1.155 

ply  Illustrates  tin-  Importance  "f  applying  exact  methods  in 
studying   the   factors   i;  •  yields.     The  facts   I  fortb   were 

obtained  from  a  study  of  the  i  hops,  and  they  ofTer  suggest ioi 

Importani  rxower.     I  rable  to  emphasize  the 

iKiint  that  the  most  profitable  methods  of  culture  and  handling  can  nol  be 

iletermlned  bj  general  observation  alone,  sin.-.'  many  details  will  be  over- 
l   which,  apparently   trifling  in   thei  le  of  great    Importance 

when  taken  in  the  the  direct   loss  due  n>  the  ' 

.]  nlone  may  not  be  appreciated  until  a  survej  is  made  and  the  percentage 
ratio  determined 

The  practlca  in  tliis  publication  were  developed  in  connec- 

tion with   an  extended   investigation  of  American   bop  growing  and   handling 
which  Is  being  m  by  Dr.  W.  W.  Stockberger,  Pharmacognosis 

bj   Mi  rhompsoi  under  il  ■    -  Di    R.  II.  True 

.  Plant   Investigations,  and  ir  ble  to 

make  these  results  immediately  avaUable  in  the  form  G.  H. 

|»'ir 


4  SOME    CONDITIONS    INFLUENCING   THE    YIELD   OF    HOPS. 

The  Bgures  given  in  this  table  were  taken  at  ten-year  intervals,  and 
in  the  absence  of  those  for  the  intervening  year.-,  they  are  of  little 
value  in  determining  either  an  increase  or  a  decrease  in  the  average 
annual  yield.  Assuming,  however,  that  the  apparent  diminution  of 
yield  for  the  State  of  California  as  indicated  by  the  table  was  real,  a 
thorough  study  of  an  individual  acre  in  the  central  part  of  the  State 
was  begun  in  L909  for  the  purpose  of  determining  some  of  the  factors 
which  might  he  responsible  for  diminished  production. 

The  results  of  this  study  clearly  indicate  that  closer  attention  to 
certain  cultural  details  should  result  in  a  substantial  increase  in  yield. 

THE  METHODS   EMPLOYED   IN   THE   INVESTIGATION. 

The  acre  selected  for  study  represented,  as  far  as  inspection 
alone  could  determine,  the  average  of  conditions  existing  in  several 
contiguous  tields  of  hops  aggregating  about  600  acre-.  The  soil,  a 
rich  sandy  loam,  had  been  under  hops  continuously  for  the  last  ten 
years.  The  rows  were  7  feet  apart,  running  from  east  to  west,  and 
the  hills  were  approximately  C-i  feet  apart  in  the  rows.  The  hops 
were  trained  on  strings  about  18  feet  long,  depending  from  the  wire-, 
of  the  usual  type  of  high-wire  trellis.'' 

When  the  crop  was  ready  for  harvesting,  a  plat  was  made  of  the 
entire  acre  and  a  definite  number  assigned  to  every  hill.  The  hops 
were  then  picked  from  each  hill  separately,  weighed,  and  the  weight 
recorded  opposite  the  number  assigned  to  that  respective  hill.  The 
number  of  vines  to  the  hill,  the  occurrence  of  male,  dwarf.  "  bastard," 
nonproductive,  and  missing  hills,  and  the  general  characteristics  of 
the  product  of  each  hill  were  also  recorded. 

EFFECT  OF  IMPERFECT  STAND  ON  YIELD  OF  HOPS. 

When  the  observations  were  tabulated  it  became  evident  that  the 
yield  had  been  heavily  reduced  through  the  occurrence  of  a  large 

number  of  nonproductive  and  missing  hills,  as  will  he  seen  from  the 
following: 

Hills  producing  Imps 853 

Hills  having  vines  with  no  hops 4:2 

Missing  hills ."it; 

Hills  with  dwarfed  vines 1 

Hills  having  '^bastard"  vines 5 

Hills  having  only  male  vines 10 

Total 967 

Deducting  the  number  of  male  hills,  the  presence  of  which  i-  held  to 
he  necessary  for  the  proper  development  of  the  crop,  there  should 

have   been    on   this   acre   (.»:>7    productive    hills,    as   against    !->">:>    hills 

'•  See  Farmers'  Bulletin  304,  i>.  14. 
[Cir.  56] 


SOME   CONDITIONS  INFLUENCING   THE  YIEU [O]  .") 

actually  bearing  I n  »|  >-.    This  gives  an  absolute  reduction  of  104  lulls, 

or  l".s  per  cent.     Had  il ntire  number  >>f  lull-  been  in  bearing  1 1  h- 

yield  would  have  been  l-.l  per  rent  greater  than  thai  actuall}  ob 
tained. 

The  distribution  <>f  the  hills  having  \  ines  with  no  ln>|>-  and  of  the 
missing  lull-  is  shown  <>n  the  accompanying  diagram   i  iiLr.  I  ).     The 


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llstrlbntlon  <•(  nonproductive  unci  missing  bills  ..f  I 
lental  acre  In  California.    #    -  Vines  bearing  no  bops;  x  _  hills. 

«l<>t-  indicate  the  hills  having  vines  bearing  no  hops,  and  the  crosses 

tln>  missing  hills.     This  distribution  appears  to  be  entirely  one  <>f 

chance  and   not  <lin-  to  variation   in  the  soil,  imperfections  in  the 
drainage,  or  other  purely  local  factors, 

[v'lr.  ."«;  ] 


b  SO.MK    CONDITIONS    ENFLUENCING    THE   YIELD    ol     EOPS. 

VARIATION  IN  THE  YIELD   FROM   INDIVIDUAL   HILLS. 

A  wide  variation  was  observed  in  the  yield  from  individual  hills. 
This  ranged  from  a  few  ounces  in  some  cases  to  as  much  as  18 
pounds  in  others.  In  making  the  records  the  weight  of  green  hop- 
was  taken  to  the  nearest  half  pound,  and  the  results  have  been  put  in 
tabular  form,  appearing  in  Table  II.  In  the  columns  marked 
"  Yield  '"  the  weight  of  green  hops  is  given  to  the  nearest  half  pound, 
and  in  the  other  two  columns  is  given  the  number  of  hills,  each  of 
which  gave  the  yield  opposite  these  numbers  in  the  adjacent  column 
to  the  left. 

Table  II. — Number  of  hills  giving  various  yields  <//  hops  <m  tin   experimental. 

acre  in  California. 


Yield. 

mils. 

Yield. 

mils. 

Pounds. 

Number. 

Pounds. 

Number. 

o. .-, 

18 

9.5 

24 

1.0 

50 

10.0 

31 

1.5 

34 

10.5 

16 

2.0 

39 

11.0 

24 

2.  5 

33 

11.5 

10 

3.0 

32 

12.0 

20 

3.5 

43 

L2.5 

:. 

4.n 

41 

13.0 

7 

4.:, 

35 

13.  5 

i. 

.Vll 

60 

14.0 

11 

5.5 

44 

14.5 

3 

6.0 

44 

15.0 

j 

6.5 

21 

15.  -'i 

i 

7.11 

49 

lti.o 

ii 

:..'. 

36 

16.5 

0 

8.0 

46 

17.1'. 

l 

8.5 

25 

17.5 

l 

9.0 

38 

18.0 

3 

The  total  yield  of  this  acre  was  .\207.5  pounds  of  green  hop';,  and 
this  divided  by  853,  the  number  of  bearing  hills,  a'ives  i',.ii)4—  pounds 
as  the  average  production  per  hill.  Of  the  entire  number  of  hills, 
47."!  were  below  the  average  and  380  hills  were  above  the  average 
production.  Also,  the  average  production  is  only  one-third  of  that 
reached  in  the  case  of  a  few  hills. 

According  to  the  quantity  of  hops  produced  the  hills  may  be 
roughly  divided  into  three  classes,  or  groups:  (1)  Those  yielding 
less  than  6  pounds.  (2)  those  yielding  from  6  to  12  pounds,  and  (.3) 
those  yielding  more  than  12  pounds.  The  first  group  consists  of  129 
hills,  or  50.1  per  cent  of  the  entire  number,  and  these  produced  only 
1,380.5  pounds,  or  26.5  per  cent  of  the  entire  yield.  The  second 
group  has  381  hills,  or  45  per  cent  of  the  entire  number,  and  the  pro- 
duction was  3,261  pounds,  or  62.6  per  cent  of  the  entire  yield.  The 
third  group  consists  of  40  hills,  or  4.7  per  cent  of  the  entire  number, 
and  i he  hop-  produced  weighed  5GG  pounds,  being  10.S  per  cent  of 

LCir.  56] 


BOME    CONDITIONS    IMI  i   ENCING     Mil'    YIELD   OP    HOPB.  7 

the  entire  yield.  The  accompanying  figure  (fig.  •_'  i  Bho*  graph- 
ically the  relationship  between  these  three  groups. 

Figure  2  will  serve,  also,  in  forming  some  conception  of  type  with 
re  i "■<■!  to  yield  from  the  hills  of  an  entire  field.     A  study  of  the  hills 

of  group  l  shows  thai   for  vslt -  reasons  thej  are  less  productive 

than  those  usually  regarded  a-  average  or  representative  hill-.  Simi- 
larly, the  hills  of  group  :'■  arc  iVw  in  number  and  may  be  considered 
as  exceptional  ami  their  occurrence  expected  far  less  -'lien  than  that 


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1'"-    -'      '•  ■<-  the  r:i t i..  of  the  Dumber  of  hills  to  the  production  of  bopa  in 

H"  of  low,  medium,  and  high  yielding  hills. 

of  the  hills  of  the  other  groups,  Ii  seems,  therefore,  that  among  the 
hills  of  group  2,  where  the  bulk  of  the  yield  was  obtained,  the  typical 

liill-  with  respect  to  yield  may  I spected  to  occur.     Assuming,  then, 

that  the  prevailing  type  of  normal  hills  with  respect  to  yield  lies 
between  those  producing  6  and  those  producing  12  pounds,  there  is 
every  reason  for  giving  special  attention  to  the  hills  low  in  yield  for 
the  purpose  of  bringing  them  to  a  higher  state  of  productiveness. 

I'lic  fact  should  not  be  losl  sight  of  that  the  average  yield  for  this 
acre,  6.1  -    pounds  per  hill,  lies  just  above  the  lower  limit  of  yield  in 
[Or.  Oti] 


8  SOME   CONDITIONS    INFLUENCING    THE    YIELD   OF    HOPS. 

the  second  group.  I  i"  through  better  methods  of  handling  and  closer 
attention  to  the  details  of  culture  the  number  of  bills  in  the  first 
group  can  be  materially  diminished,  the  average  yield  for  the  entire 
acre  will  be  correspondingly  advanced  toward  the  upper  limit  of 
yield  in  the  second  group,  and  the  total  yield  thereby  substantially 
increased.  In  the  following  pages  some  suggestions  will  be  given  as 
to  how  this  may  he  accomplished. 

RELATION  OF  NUMBER  OF  VINES  PER  HILL  TO  YIELD. 

The  records  obtained  from  the  acre  under  observation  show,  fur- 
ther, that  the  number  of  vines  trained  from  the  individual  bills 
varied  from  one  to  eight.  The  distribution  of  the  hills  according  to 
the  number  of  vines  is  shown  in  the  following: 

Hills  having  one  vine 54 

Hills  having  two  vines 113 

Hills  having  three  vines    135 

Hills  having  four  vines       186 

Hills  having  Ave  vines 188 

Hills  having  six  vines 168 

Hills  having  seven  vines 8 

Hills  having  eight  vines 1 

Total  sr,:; 

Several  explanations  of  the  variation  in  vines  to  the  hill  may  be 
advanced.  Among  them  are  the  recent  replanting  of  certain  hills, 
in  which  case  they  would  not  have  the  vigor  of  older  hills:  the  weak- 
ening of  the  roots  of  some  hills  by  disease  or  the  attacks  of  Insects; 
the  exhaustion  of  the  vigor  of  others  through  long-continued  pro- 
duction; the  breaking  off  of  a  portion  of  the  vines  in  cultivation:  the 
destruction  of  some  vines  by  the  wind;  or  the  cutting  off  of  too  many 
vines  at  the  time  of  training.  What  seems  most  probable  i>  that 
through  the  carelessness  and  negligence  of  the  workmen  the  proper 
number  of  vines  was  not  trained.  It  i-  probable,  also,  that  indi- 
vidual differences  in  vigor  and  productiveness  should  be  taken  into 
account. 

The  relation  between  the  number  of  vines  per  hill  and  the  yield 
per  hill  is  shown  in  Table  III. 

[Cir.  56] 


SOMI     CONDITIONS    INFLUENCING     I  II  I     VIELD   O]      UOl'S. 


I  v t . i  i    III      '   ■■•   •■■  the  production  o)  /<"/^  '"  tin    hill  and  tin    numbct 

I',  tin   hill. 


ill.-  hill 
1    II 
i    II 

in  -. 
II  0 
II   5 
13  0 

II  0 
II  5 

r,  5 
17  0 

hill 

I 

in 

ll 

^ 

1 

I 
17 

II 

in 
B 

l 

■ 

B 

1 

- 
11 

1 

1           1 

14 

II 

11 

- 
17              II 

11 
1 

10 

V 

7 
1                1 

in 

1 
1 

1 

II 

1 1 
II 
21 

i 

1 
1 

11 

B 

1 

14 

7 

1 
1 
1 

1 

16 

24 

1 

In 

1 

1 

11 

1 

1 

1 

• 

- 

] 

- 

In  th(>  first  column  of  the  table  the  yield  per  lull  is  given  to  the 
Dearest  half  pound.  The  figures  at  the  top  of  the  following  columns 
indicate  the  number  of  \  ines  produced  by  each  hill  <m-i-mi  ri n^r  therein, 
and  the  hills  in  each  column  are  distributed  according  to  their  produc- 
tion to  the  nearest  half  pound.  For  example,  from  column  1  it  will 
lie  seen  that  ten  L-vine  lull-  produced  0.5  pound  each,  twenty-three 
l-vine  hill-  produced  1  pound  each,  etc.;  from  column  •_'  eight  2-vine 
hills  produced  0.5  pound  each,  seventeen  2-vine  hill-  produced  1 
pound  each;  from  column  :'>  seven  3-vine  hill-  produced  1  pound  each, 
four  3-vine  hill-  produced  1.5  pounds  each,  mid  so  on  for  the  entire 
table.  At  tin-  foot  of  the  table  the  totals  -how  the  entire  number  of 
hill-  producing  the  number  of  vino-  indicated  by  the  figure  :it  th< 
of  tin'  respectn e  columns. 

A  study  of  Table  III  will  -how  thai  the  larger  numbers  in  each 
column  occur  in  groups,  but  that  the  position  of  these  groups  with 
respect  to  the  production  per  hill  i-  eery  different.  Thus  (from 
column  li   10,  23,  and  11  hills  produced  ,,.">.  1.  and  1.5  pound-  each, 


10 


SOME    CONDITIONS    INFLUENCING   THE    FIELD   OF    HOPS. 


respectively;  (from  column  3)  15.  \-2.  and  15  hills  produced  2.5,  3, 
and  3.5  pounds  each,  respectively;  (from  column  5)  14.  18,  and  18 
hills  produced  7.  7..").  and  8  pounds  each,  respectively.  From  column 
1  it  appears  that  no  1-vine  hill  produced  more  than  4  pounds,  and 
from  column  G  that  relatively  few  6-vine  hills  produced  less  than 
6.5  pounds  each.  The  balance  of  evidence,  therefore,  is  entirely  in 
favor  of  a  much  larger  total  production  when  6  vines  to  each  hill 
are  trained  than  with  a  smaller  number. 

COMPARISON  OF  ACTUAL  WITH  POSSIBLE  YIELDS  ON   1  ACRE. 

The  actual  yield  of  hops  on  the  acre  studied  was  5,207.5  pounds, 
and  the  mean  yield  per  hill  (5.104+  pounds.  Had  there  been  a  full 
stand  of  957  bearing  hills,  with  this  same  average  yield  per  hill,  the 
production  on  the  acre  would  have  been  5,841.5  pounds.  This  is  an 
increase  of  12.1+  per  cent  over  the  actual  yield. 

In  a  similar  manner,  the  possible  yield  per  acre  has  been  calculated 
for  each  number  of  vines  trained  per  hill.  For  comparison  the  results 
have  been  brought  together  in  Table  IV.  which  follows: 

Table  IV. — Possible  yield  <m  I  acre  of  hops,  according  to  the  number  of  vines 
trained,  with  the  corresponding  increase  <,r  decrease  of  the  possible  over  the 
act  nut  yield. 


Number  of  vines  to  the  hill. 


Number  ol 

hills. 


54 
113 

135 

lM, 

ISS 
168 

<-8 
••1 


U'ti'nl         Average 
vied  >"i"M  '  ' 


Pounds. 

Pounds. 

71.5 

1.324 

293.5 

2.597 

4.337 

1,168.0 

6.  -'79 

i.  188.  5 

7.917 

1.510.  5 

8.991 

81.0 

10.  125 

Average        Possible 
yield  to  yield  to 

the  vine.       the  acre. 


Pounds. 
1.324 
1.298 
1.445 
1.569 
1.583 
1.498 
1.446 


Increase  or 
decrease  of 

possible 

over  actual 

yield. 


Pounds. 
1 .  257.  0 
2,485.3 
4.150.5 
6.009.0 
7.570.5 
8,604.3 


Per  cent, 
a  75.  8+ 
a  52.  2+ 
a  20.  2+ 
6  15.3  + 
6  45.  4+- 
6  65.  2+ 


1  )i  •crease. 


'■  Ineivas 


Number  of  hills  too  small  for  consideration. 


The  average  yield  to  the  hill  was  determined  in  each  case  by  divid- 
ing the  number  of  pounds  produced  by  all  of  the  hills  having  the 
same  number  of  vines  by  the  number  of  such  hills.  The  possible 
yield  was  then  obtained  by  multiplying  the  average  yield  per  hill 
by  957,  the  number  of  possible  bearing  hills  to  the  acre.  It  will  be 
observed  that  the  possible  yield  in  the  case  of  the  hills  having  1.  2, 
and  o  vines,  respectively,  is  very  much  less  than  the  actual  yield, 
which  was  5,207.5  pounds.  Also,  in  the  case  of  the  hills  having  I.  5, 
and  6  vines,  respectively,  the  possible  yield  is  far  in  excess  of  the 
actual,  being  65.2+  per  cent  greater  for  the  6-vine  hills. 

[Cir.  56] 


Ml     I  0ND1  I  l<>\-   INFLUENCING     I  III     YIELD   OP    HOPS.  1  1 

Ii  should  be  noted  that  1 1 1 « -  average  yield  per  vine  is  fairl}  « -» » i • 
stant,  irrespective  of  the  number  of  vines  to  the  lull.     The  average 
yield   per  vine   for  the  entire  acre  also  i-losch    accords  with   thi 
figures,  being  in  this  case  1.513  pounds  per  Tine. 

Tile  averages  given  in  Table  IV  tnaj  be  considered  as  applying 
not  only  in  the  acre  studied,  but  also  in  a  general  waj  t<>  the  entire 
crop  in  the  section  where  this  work  was  done.  So  long  as  the  general 
conditions  remain  unchanged  there  is  ;i  high  degree  of  probability 
that  these  averages  will  be  found  to  represent  fairly  well  what  may 
be  expected  in  succeeding  years.  Changed  weather  conditions,  at 
tacks  of  lice,  mold,  and  spiders,  or  other  unfavorable  influences  to 
which  the  hop  crop  is  subject,  will  of  course  materially  affect  the 
chance  of  these  averages  being  repeated.  But  thej  do  -how  that  a 
greal  increase  in  yield  maj  be  reasonably  anticipated  in  fields  in 
which  there  is  a  full  stand  and  6  vines  arc  trained  t«>  each  hill  over 
the  entire  field  when  it  presents  the  conditions  existing  on  the  acre 
which  has  furnished  the  data  for  these  observations, 

THE    SO-CALLED    •BASTARD"    VINES. 

Iii  -nine  sections  hop  vines  are  occasionally  found  which  hear  both 
-laminate  and  pistillate  flowers.  Such  plants  are  known  locally  as 
"bastards,"  "mongrels,"  or  "bull-hops."  When  they  occur  they 
represent  a  total  loss,  so  far  as  yield  is  concerned,  since  the  few  hops 
borne  by  these  vines  are  inferior  and  never  gathered.  On  the  acre 
under  consideration  there  were  only  five  of  these  plants,  but  they 
have  been  observed  in  much  greater  proportion  in  other  years  and  in 
other  localities. 

There  is  no  e\  idence  that  these  vines  usually  occur  n<  ar  a  male  vine, 
as  stated  by  Myrick;  neither  can  an  excess  of  pollen  falling  upon 
the  pistillate  flowers  produce  this  abnormality,  as  is  believed  by  some 
to  be  the  case.  Plain-  of  this  type  frequently  occur  among  seedling 
hop-,  and  their  presence  may  he  expected  in  held-  where  chance  seed- 
lings springing  up  near  the  permanent  hills  have  been  trained  in  the 
usual  manner.  There  are  also  good  reasons  for  believing  thai  this 
undesirable  characteristic  may  be  introduced  through  the  root  cut- 
tings used  in  replanting  or  in  setting  out  new  held-.  In  L908  a  num- 
ber of  cuttings  were  taken  from  one  of  these  "bastard"  plant-  and 
removed  to  a  locality  about  In  miles  distant.  The  vines  from  these 
cuttings  came  into  flower  in  1909  and  in  every  case  reproduced  the 
malformation  of  the  original  plant  from  which  they  were  taken.  In 
view  of  this  fact  care  should  be  taken  to  prevent  the  use  of  cuttings 
from  ••  bastard  "  plant-  by  promptly  digging  them  out  and  destroying 

Myri.k.  II.    The  Bop,  New  Sort,  1889,  p.  23. 
[Cli 


12  SOME    CONDITIONS    INFLUENCING    THE    YIELD    OF    HOPS. 

the  roots  as  soon  as  they  arc  observed.     In  this  way  their  perpetuation 
may  be  prevented  and  the  loss  in  yield  due  to  their  occurrence  avoided. 

SUMMARY. 

A  critical  study  of  yield  on  an  acre  of  hops  in  California  selected 
as  representing  the  average  condition  of  600  surrounding  acres  show- 
that,  owing  to  the  occurrence  of  a  large  number  of  nonproductive  and 
missing  hills,  the  actual  yield  was  only  87.9  per  cent  of  what  might 
be  expected  with  a  perfect  stand. 

The  yield  from  individual  hills  was  found  to  vary  from  0.5  to  18 
pounds.  Owing  to  the  large  number  of  low-yielding  hills  the  average 
yield  per  hill  for  the  entire  acre  was  reduced  to  G.lO-t-f-  pounds. 

The  number  of  vines  trained  to  each  hill  varied  from  one  to  eight. 
As  the  number  of  vines  per  hill  increased,  the  average  yields  of  the 
hills  having  the  same  number  of  vines  were  found  to  increase  in 
approximately  the  same  ratio. 

Assuming  a  full  stand  of  957  hills  with  G  vines  trained  to  each  hill, 
the  calculated  possible  yield  is  65.2-f-  per  cent  greater  than  the  actual 
yield  on  this  acre. 

"Bastard"  or  "mongrel"  hills  should  be  dug  out  and  destroyed, 
as  they  are  of  no  value  and  diminish  the  total  yield. 

Approved : 

James  Wilson, 

Secretary  of  Agriculture. 

Washington,  D.  C,  March  7,  1910. 

[Cir.  ■",<;] 

o 


N         V 


UNIVERSITY  OF  FLORIDA 


3  1262  08928  9762 


